'Red flags' noted in sewer line that failed

A suing attorney cites a report in which the city reveals a past spill

A report on the city's worst raw sewage spill contains several "red flags" that Waikiki's largest pressurized sewage main was deteriorating before the break, an attorney said yesterday.

Chris Sproul, an attorney for environmental groups suing the city for Clean Water Act violations, said he didn't realize until reading the city's spill report to the Environmental Protection Agency that the Beachwalk force main had failed in the past.

The EPA had required the report after the city dumped 48 million gallons of raw sewage into the Ala Wai Canal last month. The city released the report yesterday.

"EPA will work with the Hawaii Department of Health, the city and the community to make use of the lessons learned from this spill so effective action can be taken to minimize the risk of another catastrophic spill," Kathi Moore, manager of the EPA region's Clean Water Act Compliance Office in San Francisco, said in a written statement.

EPA officials would not comment on the specifics in the report.

The March 24-29 raw sewage spill from the Beachwalk main was Oahu's largest ever. It led to contaminated water postings at surf sites near the mouth of the canal for more than a week, and closed Waikiki beaches for three to seven days.

Though only 510 gallons of sewage was spilled during a 1993 repair of a hairline fracture, Sproul called that spill "a warning, the canary in the coal mine."

"They should have, at minimum, thoroughly inspected the condition of the entire line after that," Sproul said. "Yet they acknowledge in the report that they still haven't fully inspected the condition of the line."

Sproul is a San Francisco-based attorney for the Sierra Club, Hawaii's Thousand Friends and Our Children's Earth, plaintiffs in a pending lawsuit against the city for federal Clean Water Act violations because of spills from city sewage force mains. Settlement talks among parties to the lawsuit began in March and are set to continue in May, he said.

According to Sproul, a crack in a concrete line is serious, since it could let underground saltwater begin deteriorating its metal reinforcement.

City "engineers observed cracks in the sidewalks and pavement along Kaiolu Street and signs of uneven settlement in the area of the force main," the city report said. "Engineers also noted that a pile-driving construction activity was taking place approximately 200 feet west of the force main rupture location."

The city's report didn't conclude what caused the sewer main break, but offered that "heavy rains, area ground settlement, and near-by pile-driving activities have been identified as possible contributing factors to the rupture."

City Environmental Services Director Eric Takamura said yesterday that he was "relieved" to have turned in the report to the EPA, but said it does have gaps. Among those are calculations of how much sewage workers were able to divert to the nearby Fort DeRussey force main, which kept it from going into the Ala Wai Canal. "They're still working on that," he said.

The break occurred at a "bell joint," where there were at least three cracks in the 42-inch diameter pipe and a rubber gasket at the joint was dislodged, the city's report said.

The report also notes that because of rain water infiltrating the sewer lines, "at the Beachwalk Pump Station, all four pumps had to be turned on to accommodate this increase in flows. This may have caused a pressure surge within the force main and with the already saturated soils, may have caused the pipes to deflect further."

Sproul said: "Poorly maintained sewer lines leak, which means they get a lot of rain water in the system when it rains. ... They were overpressurizing an old, vulnerable line -- trying to deal with leaky pipes that let in too much rainwater -- and they blew it. It popped the line."

The EPA's Moore wrote: "One lesson is that the wastewater infrastructure on Oahu is vulnerable to breakdowns. Although this issue is not new, the spill underscores the urgent need to protect the public and environment from the risk of future system failures."

CINDY ELLEN RUSSELL / CRUSSELL@STARBULLETIN.COM
Workers survey the sewage main on Kaiolu Street near the Ala Wai on March 29.

LARGEST SEWAGE SPILL IN HAWAII HISTORY

Here's a timeline of key events in the city's response to the Beachwalk pressurized main spill March 24-29:

» March 24: Force main rupture on Kaiolu Street reported at 7:20 a.m.; city crews arrive at 8:33 a.m.; contractor arrives at 10:30 a.m.; they dig to the top of the leaking pipe by 1 p.m.; at 8:10 p.m. heavy flooding from rain stops work; a worker falls in the flooded pit but isn't injured. Pumper trucks continuously remove leaking sewage from the pit.

» March 25: At 4:52 p.m., a diver goes into the now deeper, still sewage-filled excavation pit to locate extent of damage to pipe; at 9:30 p.m., diver attempts to fix pipe rupture; it doesn't hold. At least one 10-inch pipe sending sewage into Ala Wai Canal.

» March 26: At 5:30 p.m., multiple mobile pumps with 10-inch lines are put in place to divert sewage from the pipe to the Ala Wai Canal; preparations are made to "de-water" the excavation pit for dry repairs.

» March 27: Carpenters prepare wooden forms to hold rebar for a concrete pour. Cracks in pipe patched with epoxy and Fiberglas wrap.

» March 28: High-strength concrete poured over the patched pipe.

» March 29: At 9:55 a.m. workers begin shutting down the lines that have been diverting sewage into the Ala Wai Canal. The Beachwalk pumping station is powered up gradually to make sure the fix will hold.

That afternoon, Mayor Mufi Hannemann announces the fix is working -- but that the beaches fronting the Hilton Hawaiian Village and Hale Koa Hotel will be closed because of high bacteria counts.

Source: City report to the Environmental Protection Agency

19 sewage spills of at least 1,000 gallons hit in March

According to the state Health Department's Clean Water Division, the City of Honolulu had 19 sewage spills of 1,000 gallons or more in March. In addition to the Ala Wai Canal spill of 48.6 million gallons, they included:

» Two spills at Sand Island Wastewater Treatment Plant that released a total of 164,000 gallons.

» Four spills at the Waimanalo Wastewater Treatment Plant for a total of 211,510 gallons, a portion of which was partially treated.

» Spills from manholes and collection pipes ranged in size from fewer than 100 gallons to as much as 31,320 gallons in a March 3 spill in Kailua's Keolu Hills and 23,200 gallons in a March. Many of those were in Kailua and Kaneohe, but Kaimuki, Kalihi, Nuuanu, Wahiawa and Mililani all had spills. Total from smaller spills was about 76,400 gallons.

» Throughout March there was a sewage spill warning sign up at 17 different locations (counting the multiple postings from the Ala Wai spill as one location) for a total of 184 posted days on Oahu. As of water quality tests taken Saturday, the Ala Wai Canal, Ala Wai Harbor, Ala Moana canoe launch ramp and several sites on Kaneohe Bay remain posted.